Mortgage Banking Activity - Residential Mortgage Loans (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended |
|---|---|---|
Mar. 31, 2026 |
Dec. 31, 2025 |
|
| Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward] | ||
| Balance at beginning of period | $ 406 | |
| Balance at end of period | 562 | $ 406 |
| Mortgage loans | ||
| Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward] | ||
| Balance at beginning of period | 147 | 81 |
| Originations and purchases | 339 | 1,253 |
| Sales, net of gains | (323) | (1,187) |
| Balance at end of period | $ 163 | $ 147 |